Production of drying oils



United States Patent iice 2,885,297 PRODUCTION or DRYING ons Kurt Hans Reisinger, Stockholm, Sweden, assignor to Richard Nilsson Aktiebolag, Stockholm, Sweden, a corporation of Sweden No Drawing. Application July 30, 1956 Serial No. 600,729

Claims priority, application Sweden July 11, 1951 8 Claims. (Cl. 106-123) The present invention relates to a new method of pro ducing film-forming drying oils. This is a continuationin-part of my copending application Serial No. 258,539, filed November 27, 1951, now abandoned.

It is an object of the present invention to produce filmforming drying oils having improved properties in many respects as compared to linseed oil and other drying oils hitherto used.

A further object of the invention is the production of oils of the character described which can be used, for example, for lacquers, paints, varnishes, and other protective coatings, and which are adapted to furnish strong, more or less elastic films, resistant against any type of corrosion. The oils can, furthermore, be used for the impregnation of textile fabrics, paper, and other fibrous material.

With these objects in view, the method according to the invention substantially consists in preparing a solution, hereinbelow called first solution, by dissolving, in an inert solvent, one or more saturated or unsaturated higher aliphatic acids, for example, saturated fatty acids, or saturated cyclic acids, or mixtures of the same; preparing a second solution by dissolving one or more aluminum. alcoholates, such as aluminum butylate, amylate, or hexylate in an inert solvent, and thereafter converting the aluminum alcoholates into enolic aluminum compounds, and subjecting the first solution to a condensation reaction with the second solution in the absence of water and substances which generate water during the condensation. The quantity of the second solution is so chosen as to contain a substoichiometric amount of aluminum enolate with respect to the acid present in the first solution.

Preferably, the higher aliphatic acids contain at least 8 carbon atoms. Generally I prefer to use fatty acids having between 10 and 20 carbon atoms. Examples of such acids are: Palrnitic acid, coconut acids, stearic acid, whale oil fatty acids and the like. The acid solution may contain refined tall oil or carboxylic acids contained in such oil. As already mentioned, a mixture of several acids may be used for the first solution.

The solvents for the acids and for the aluminum compound may consist of aliphatic or aromatic hydrocarbons, such as gasoline, xylene, benzene, and so on.

It is already known to produce metal soaps, particularly aluminum soaps by reaction of the corresponding aluminum alcoholates with fatty acids, but it is to be understood that the products obtained by the method according to the present invention are not aluminum soaps, but film-forming drying oils. In the process according to the invention, the production of aluminum soaps is avoided, because of the undesirable propertiesof these soaps. If aluminum soaps were. obtained unintentionally, they would be a gelatinous mass, even when diluted to a high extent, so that they would be useless for production of film-forming drying oils.

According to the invention, then, the reaction between the aluminum compounds and the fatty acids is directed to the formation of drying, film-forming oils by maintaining a predetermined ratio between the aluminum alco- 2,885,297 Patented May 5, 1959 holate and the tautomeric compound present in the reaction mixture, this ratio being at least one molecule aluminum alcoholate to one molecule of the tautomeric compound. By maintaining this ratio, the formation of gelatinous masses which could interfere with the production of the drying oils is safely prevented.

The conversion of the aluminum alcoholate into enolic form is carried out by heating the solution of the alco holate with the stoichiometric amount of a tautomeric' compound in enolic form for a period of from 1 to 3 hours in a temperature range of 100-135 C., according to the boiling points of the tautomeric compound and the solvent.

As means for the intended conversion, preferably, the following compounds are used in their enolic form: Diketones, diketo-carboxylic acid esters, dicarboxylic acid esters of the malonic-ester type, keto-aldelhydes, and beta keto esters.

Enolization by means of the ketonic additive is most effectively done when the parent carbonyl group, i.e. the enol-forming group and not the carbonyl group of carboxyl or aldehyde compound, is situated in a beta position to the nearest functional group. Hence, from the above listed keto-compounds, the beta-keto compounds are the most effective. Furthermore it has been found that unsaturated compounds give superior results over saturated. As examples of either saturated or unsaturated compounds to be used for the enolization, I mention the following: Acetone, malonic diesters, laevulinic acid esters, and acetoacetic esters. It should, of course, be understood that this is by no means a complete list.

The presence and the generation of water and of free organic acids must be carefully avoided. The starting materials used are in dry form, and reactions are excluded during which water or free organic acids could be formed by chemical interaction.

The amount of aluminum (in solution) to be used with the fatty acids (likewise in solution) depends primarily on the amounts of fatty acids used and their acid number, furthermore on the equilibrium of the enolic and the alcoholic form of the aluminum compound used, and the desired properties of the film-forming oils.

Generally speaking, the drying oils contain between 0.5 to 2.5% by weight of aluminum, and in any case the quantity of the aluminum compound should be substantially smaller than the equivalent amount of the acid in solution.

0n the other hand, the concentration of the aluminum in the solvent is without importance. For dissolving the organic aluminum compound, any desired aliphatic or aromatic hydrocarbon may be used without affecting the quality of the resulting oils.

The heating period is independent of the concentration of the acids used, and so is the temperature. The latter only depends on the solvents used, and ranges in general presence of the last mentioned compounds prevents the formation of soaps. The existence of co-valencies explains the formation of molecule chains as a presupposition for the drying mechanism.

When unsaturated fatty acids are used, the well known auto-oxidation in the side chains of the fatty acids is a parallel and additional reaction to the first mentioned one.

The method according to the invention will now be more fully described in a number of examples which are given by way of illustration and not of limitation.

7 Example 1.-As a first solution I prepare a solution of 200 g. stearic acid in 250 g. warm white spirit. Then I start preparing the second solution by heating 246 g. of Al-butylate with,188 g. of malonic acid diethylester for 2'-3 hours, until the practical test shows that the enolization has been completed.

450 g. of a solution of this compound in white spirit, containing 1.55% metallic aluminum, or 6.2% of the said aluminum compound, are added to the first solution and the mixture is heated for half an hour. The final product is a drying oil with a viscosity of 40-50 DIN- sections (Ford Cup).

Example 2.-As a first solution I prepare a solution of 400 g. hydrogenated whaleoil fatty acids in 300 g. white spirit. Then I start preparing the second solution by heating 246 g. of Al-butylate with 104 g. acetoacetic ester for 23 hours until the practical test shows that the enolization has been completed.

300 g. of a solution of said aluminum compound in white spirit, containing 1.5% metallic aluminum, or 16.8% of the organic aluminum compound respectively, are added to the first solution and the mixture'is heated for half an hour.

Viscosity of the final product: 160-170 DIN-seconds.

Example 3.-As a first solution I prepare a solution of 300 g. coconut fatty acids in 200 g. xylene. Then I prepare the second solution by heating 246 g. of Albutylate with 114 g. acetonylacetone for 2-3 hours until the practical test shows that the enolization has been performed.

500 g. of solution of this aluminum compound, containing 2.5% aluminum or 24.3% of the aluminum compound itself, respectively, are added to the first solution and the mixture is heated for half an hour.

Viscosity of the final product: 40-50 DIN-seconds.

Example 4.-As a first solution I prepare a solution of 200 g. of mixed fatty acids (acid number 205, iodine number 15, melting point 45 C.) in 300 g. white spirit. Then I make the second solution by heating 246 g. of Albutylate with 91 g. acetoacetic ester for 2-3 hours, until the practical test shows that the enolization has been performed.

450 g. of a solution of this aluminum compound, containing 2.25% aluminum or 25% of said aluminum compound, respectively, are added to the first solution and the mixture is heated for half an hour.

Viscosity of the final product: 285 DIN-seconds.

Example 5.As a first solution I prepare a solution of 400 g. commercial tall oil (acid number 180, containing 90% free fatty acids) in 200 g. Tetraline (tetrahydronaphthalene). Then I start preparing the second solution for 2-3 hours, until the practical test shows that the enolization has been performed.

400 g. of this aluminum compound, dissolved in toluene, containing 1.8% aluminum, or 22.9% of the organic aluminum compound, respectively, are added to ihe first solution and the mixture is heated for half an our.

Viscosity of the final product: 230-250 DIN-seconds.

Example 6.As a first solution I prepare a solution of 400 g. distilled tall oil (acid number 200) in 175 g. white spirit. Then I prepare the second solution by heating 246 g. of Al-butylate with 130 g. acetoacetic ester for 2-3 hours, until the practical test shows that the enolization has been carried out.

425 g. of this aluminum compound, dissolved in xylene, containing 229 g. of the said aluminum compound, are added to the first solution and the mixture is heated for half an hour.

Viscosity of the final product: 120 DIN-seconds.

Example 7.As a first solution I prepare a solution of 300 g. fatty acids from linseed oil rafiination in 584 g. white spirit. Then I make the second solution by heating 246 g. of Al-butylate with 104 g. acetoacetit; ester for 2-3 hours, until the practical test shows that the enolization has been carried out.

116 g. of said compound dissolved in white spirit, containing 84 g. of the said compound, are added to the first solution and the mixture is heated for half an hour.

Viscosity of the final product: -100 DIN-seconds.

Example 8.-As a first solution I prepare a solution of 250 g. phenyl acetic acid in 426 g. white spirit. Then I prepare the second solution by heating 246 g. of A1- butylate with g. acetoacetic ester for 2-3 hours until the practical test shows that the enolization has been carried out.

324 g. of this aluminum compound dissolved in xylene containing 236 g. of the said organic aluminum compound are added to the first solution and the mixture is heated for half an hour.

Viscosity. of the final product: 130-135 DIN-seconds.

While in the above examples I described particularly the use of Al-butylate, it shoud be understood that I can use with equally good results Al-hexylate or Al-amylate, when so desired.

What I claim is:

1. A method of producing film-forming drying oils comprising the steps of preparing a first solution by dissolving, in an inert hydrocarbon solvent, at least one organic carboxylic acid having from 8-20 carbon atoms and being selected from the group consisting of saturated fatty acids, unsaturated fatty acids, and carbocyclic fatty acids; preparing a second inert hydrocarbon solution of an enolic aluminum compound obtained by reacting an aluminum alcoholate whose alcoholic component is selected from the group consisting of a butylate, an amylate, and a hexylate with an enolic compound selected from the group consisting of diketones, diketocarboxylic acid esters, malonic esters, ketoaldehydes, beta keto esters and acetone, mixing the first solution with a quantity of the second solution containing a substoichiometric amount of aluminum with respect to the acid in the first solution said substoichiometric amount being approximately two molecules of carboxylic acid from said first solution to one atom of aluminum from said second solution, the quantity of said second solution based upon the acid number of said first solution and the aluminum content of said second solution, and heating at a temperature above 100 C. to about C. the mixture to bring about a condensation between the acid and the aluminum enolate free from water and of substance capable of generating water during the condensation.

2. The method as claimed in claim 1, wherein said first solution contains refined tall oil.

3. The method as claimed in claim 1, wherein said first solution contains a mixture of carboxylic acids obtained from tall oil.

4. A method of producing film-forming drying oils comprising the steps of preparing a first solution by dissolving stearic acid in white spirit, preparing a second inert hydrocarbon solvent solution of an enolic aluminum compound obtained by reacting aluminum butylate with malonic acid diethylester, mixing the first solution with a quantity of the second solution containing a substoichiometric amount of aluminum with respect to said acid in the first solution, and refluxing the mixture for half an hour to bring about a condensation between the acid and the aluminum enolate.

5. A method of producing film-forming drying oils comprising the steps of preparing a first solution by dissolving hydrogenated whale oil fatty acids in white spirit, preparing a second inert hydrocarbon solvent solution of an enolic aluminum compound obtained by reacting aluminum butylate with aceto acetic ester for 23 hours, mixing the first solution with a quantity of the second solution containing a substoichiometric amount of aluminum withrespect to said acid in the first solution, and

refluxing the mixture for half an hour to bring about a condensation between the acid and the aluminum enolate.

6. A method of producing film-forming drying oils comprising the steps of preparing a first solution by dissolving coconut fatty acids in xylene, preparing a second inert hydrocarbon solvent solution of an enolic aluminum compound obtained by reacting aluminum butylate with acetyl acetonate for 2-3 hours, mixing the first solution with a quantity of the second solution containing a substoichiometric amount of aluminum with respect to said acid in the first solution, and refluxing the mixture for half an hour to bring about a condensation between the acid and the aluminum enolate.

7. A method of producing filrn-forming drying oils comprising the steps of preparing a first solution by dissolving tall oil in tetraline, preparing a second inert hydrocarbon solvent solution of an enolic aluminum compound obtained by reacting aluminum butylate with malonic acid diethyl ester for 23 hours, mixing the first solution with a quantity of the second solution con-"taining a substoicbiometric amount of aluminum with respect to said acid in the first solution, and refluxing the mixture for half an hour to bring about a condensation between the acid and the aluminum enolate.

8. A method of producing film-forming drying oils comprising the steps of preparing a first solution by d.issolving phenyl acetic acid in white spirit, preparing a sec ond inert hydrocarbon solvent solution of an enolic aluminum compound obtained by reacting aluminum butylate with aceto acetic ester for 2-3 hours, mixing the first solution with a quantity of the second solution containing a substoichiometric amount of aluminum with respect to said acid in the first solution, and refluxing the mixture for half an hour to bring about a condensation between the acid and the aluminum enolate.

References Cited in the file of this patent UNITED STATES PATENTS 2,160,532 Barrett May 30, 1939 2,242,230 Burr May 20, 1941 2,424,458 Heijmer July 22, 1947 2,513,825 Sorenson July 4, 1950 2,634,279 Kuhrt Apr. 7, 1953 

1. A METHOD OF PRODUCING FILM-FORMING DRYING OILS COMPRISING THE STEPS OF PREPARING A FIRST SOLUTION BY DISSOLVING, IN AN INSERT HYDROCARBON SOLVENT, AT LEAST ONE ORGANIC CARBOXYLIC ACID HAVING FROM 8-20 CARBON ATOMS AND BEING SELECTED FROM THE GROUP CONSISTING OF SATURATED FATTY ACIDS, UNSATURATED FATTY ACIDS, AND CARBOCYCLIC FATTY ACIDS; PREPARING A SECOND INERT HYDROCARBON SOLUTION OF AN ENOLIC ALUMINUM COMPOUND OBTAINED BY REACTING AN ALUMINUM ALCOHLATE WHOSE ALCOHOLIC COMPONENT IS SELECTED FROM THE GROUP CONSISTING OF A BUTYLATE, AN AMYLATE, AND A HEXYLATE WITH AN ENOLIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF DIKETONES, DIKETOCARBOXYLIC ACID ESTERS, MALONIC ESTERS, KETOALDEHYDES, BETA KETO ESTERS AND ACETONE, MIXING THE FIRST SOLUTION WITH A QUANTITY OF THE SECOND SOLUTION CONTAINING A SUBSTOICHIOMETRIC AMOUNT OF ALUMINUM WITH RESPECT TO THE ACID IN THE FIRST SOLUTION SAID SUBSTOICHIOMETRIC AMOUNT BEING APPROXIMATELY TWO MOLECULES OF CARBOXYLIC ACID FROM SAID FIRST SOLUTION TO ONE ATOM OF ALUMINUM FROM SAID SECOND SOLUTIN, THE QUANTITY OF SAID SECOND SOLUTION BASED UPON THE ACID NUMBER OF SAID FIRST SOLUTION AND THE ALUMINUM CONTENT OF SAID SECOND SOLUTION, AND HEATING AT A TEMPERATURE ABOVE 100* C. TO ABOUT 135* C. THE MIXTURE TO BRING ABOUT A CONDENSATION BETWEEN THE ACID AND THE ALUMINUM ENOLATE FREE FROM WATER AND OF SUBSTANCE CAPABLE OF GENERATING WATER DURING THE CONDENSATION 